#include "stdio.h"
long long arr[1000];
long long fibo(int n)
{
	if (n<=2) return 1;
	else if (arr[n] == 0) arr[n] = fibo(n-2)+fibo(n-1);
	return arr[n];
}
int main()
{
	int n;
	printf("%s", "Enter a number:\n");
	scanf("%d", &n);
	printf("%lld", fibo(n));
	return 0;
}